Glow sticks are plastic tubes containing glass vials that emit
light after the stick is "cracked". They are ideal for anytime when
electric lights are not a viable light source, such as during power outages,
or when investigating gas leaks. They are also often used as party favors.

There are three main components of glow sticks, two chemicals
that react to release energy and also a fluorescent dye to accept this energy
and convert it into light. Common commercial light sticks contain a solution
of a phenyloxalate ester and a florescent dye and glass ampoule containing a
hydrogen peroxide solution. The structure of the fluorescent dye determines
the resulting color of the glow stick when the chemical solutions are mixed.

To get the stick to produce light, it is necesary to "crack"
the stick. This requires bending the stick, until the glass vial contained within
the plastic casing breaks. This allows the inside the glass to mix with the
chemicals outside the glass vial. Once these chemicals contact one another,
a reaction takes place. The chemical reaction in a glow stick releases energy
in the form of light. This light along with dye allows the stick to glow the
brilliant colors that we observe.